1. Field of the Invention
The present invention relates to an image processing apparatus such as a copying apparatus, and more particularly to an apparatus for effecting marker edition in accordance with information having a color marked by a color marker on a document sheet.
2. Related Background Art
In a color copying machine, a marker edition function to encircle or trace a desired area by a commercially available marker pen on a black-and-white document sheet to color the area has been proposed. Such a marker edition function usually has a plurality of modes such as a paint mode in which inside of a desired closed section 1000 defined by a black line on a document sheet having white underground is colored by a blue marker 1001 as shown in FIG. 37A so that an entire closed section is colored in blue for print-out as shown in FIG. 37B and a line mode in which a periphery of a desired black line 1002 on a document sheet having white underground is colored by a red marker 1003 as shown in FIG. 38B so that the black line is converted to a red line for print-out.
The determination of the paint mode shown in FIGS. 37A and 37B is first explained. During a read operation of an image of FIG. 37A, assuming that a read line at a given timing is a line A and an output sequence of pixel data is that shown by an arrow, color data is outputted in a sequence of . . . white, black, blue, white, . . . , white, blue, black, white. Accordingly, by detecting the presence of black immediately before first appeared blue, it is determined that the paint mode has been started from the first blue pixel. By detecting that black is immediately after the last blue, it is determined that the paint mode has been terminated with the last blue pixel. Accordingly, the paint mode is attained by outputting all pixels (blue, white, . . . white, blue) during the paint mode as blue data.
The determination of the line mode shown in FIGS. 38A and 38B is now explained. During a read operation of the image of FIG. 38A, assuming that a read line at a given timing is line B and an output sequence of image data is that shown by an arrow, the color data is outputted in a sequence of . . . , white, red, black, . . . black, red, white, . . . . Accordingly, by detecting the presence of white immediately before the first appeared red, it is determined that the line mode has been started from the first red pixel. By detecting that white is immediately after the last red, it is determined that the line mode has been terminated with the last red pixel. Accordingly, the line mode is attained by outputting the red pixels and the black pixels of the pixels (red, black, . . . , black, red) during the line mode as the white data and the red data, respectively.
In this manner, the starting mode is determined depending on whether the pixel immediately before the pixel for which the marker color is first detected is white or black, and when the starting mode is the paint mode, the mode is terminated when the pixel immediately after the pixel for which the marker color is lastly detected is black, and when the starting mode is the line mode, the mode is terminated when the pixel immediately after the pixel for which the marker color is lastly detected is white.
However, the color conversion mode is determined by the marker coloring by a user, and as shown in FIG. 39A, the user may desire the line mode process for a document sheet image 1004 but a color 1005 may appear by irregular painting during overpainting by the marker. Since the color 1005 is darker than a normally painted color 1006, the color 1005 and the color 1006 are determined as different colors and a resulting output is produced as shown in FIG. 39B.
The color of the sheet used for the document sheet is mainly white but because it may be slightly colored such as a recycled sheet, the color of the marker pen is not uniform or a characteristic of a color filter for reading the document sheet is not uniform, the read colors may be misdetermined and an output which is not intended by the user is resulted in.
The color of the marker differs from country to country even if it has the same label (for example, red). Further, the number of colors of the marker pens available in the market place is not uniform that is, five in one country and eight in other country. As a result, it is difficult to correctly recognize the colors of the color marking pens marketed worldwide and the misdetermination of the color occurs.